feat: Introduce Summary and Professional skills, replacing the old style mode and text structuring configuration options.

Core/Skills/ProfessionalSkill.cs

@@ -0,0 +1,26 @@
+namespace Toak.Core.Skills;
+
+public class ProfessionalSkill : ISkill
+{
+    public string Name => "Professional";
+    public string Description => "Rewrites the spoken text to sound highly professional and articulate.";
+    public string[] Hotwords => new[] { "System professional", "System rewrite professionally", "System formalize" };
+
+    public bool HandlesExecution => false;
+
+    public string GetSystemPrompt(string rawTranscript)
+    {
+        return @"You are an expert formal editor and corporate communicator.
+The user wants to rewrite the following text professionally. The transcript might start with a hotword like 'System professional'.
+- Enhance the text from the speaker to sound highly professional and articulate.
+- Maintain the exact meaning and key information of the original transcription.
+- Ensure paragraph breaks are added logically to prevent walls of text, improving readability.
+- Avoid filler words, hesitations (umm, uh), or conversational redundancies.
+- Output ONLY the final polished text. Do not include markdown, explanations, or quotes.";
+    }
+
+    public void Execute(string llmResult)
+    {
+        // Not used since HandlesExecution is false
+    }
+}